According to a statement from the Los Angeles County Sheriff’s Department obtained by Yahoo Lifestyle, the suspect crashed his car into a Carl’s Jr. restaurant in Palmdale, Calif. By the time officers arrived on the scene, the man had fled the vehicle and run across the street to a nearby McDonald’s, taking off all his clothes in the process.

Armed with a knife, the unidentified man ran into the McDonald’s, where he stabbed an elderly customer, described by local affiliate KCAL 9 as an 88-year-old man dining with his grandson. Authorities say the man is in stable condition.

The assailant then exited the restaurant, attacking a guard employed by McDonald’s on his way out. The guard responded by shooting him in the upper torso. The suspect, described as a Hispanic male, was taken to a local hospital, where he was pronounced dead.

“I see a man standing right here,” witness Irvin Diaz told KCAL 9. “And all I heard was ‘pop, pop.’ And I came over and saw this man on the ground. He was naked, holding his stomach.”

Homicide detectives have launched an investigation into what might have prompted the attack.